The present disclosure is related with an image forming apparatus and an image formation method suitable for changing between a normal mode and the sleep mode.
An image forming apparatus is MFP (Multifunction Peripheral), such as a printer, a multifunction printer, multifunctional peripheral equipment, or the like. As energy conservation measures, when set-up time passes in the state where a user does not use the image forming apparatus, the image forming apparatus shifts to a state of energy saving (henceforth a “sleep mode”). However, once it shifts to the sleep mode, it takes time until shifting to a state where an image forming apparatus can be used for the user (henceforth a “the normal mode”).
That is, for example, a host computer transmits information request data for confirming information of an image forming apparatus to the image forming apparatus in the sleep mode via a network. In this case, the image forming apparatus shifts from the sleep mode to the normal mode and then transmits the response data, and thus it requires time. Therefore, when information request data is transmitted from the host computer, repeatedly, the number of times for shifting from the sleep mode to the normal mode increases. Since time to be in the sleep mode is short, the energy-saving effect reduces.
As this measure, a typical case enables also to transmit the response data in the sleep mode. For example, in the image processing apparatus of the typical case, a controller having two CPUs (Central Processing Unit,) that are main CPU for responding in the normal mode and sub CPU for responding in the sleep mode, is used.
At first, in the normal mode, main CPU memorizes response data in RAM (Random Access Memory) in main CPU. When shifting to the sleep mode, sub CPU extracts the frequently-used response data from RAM in main CPU and memorizes to RAM in sub CPU.
Thus, when shifting from the normal mode to the sleep mode, the frequently-used response data is memorized in RAM in sub CPU. Therefore, during the sleep mode, sub CPU can use the data memorized in RAM in sub CPU, make the response data, and transmit it.